It really is impossible to tell.
there are two ways this could end
Either it will come as a shock or an expected end will happen.
It's all up to Kishi, he is God after all - i mean in narutoverse.
I don't know because Naruto still love Sakura -.- But.. I think it will be Hinata because she says that she loves him, and then he was so..so...Silent! : P